The present invention relates to a compressor which compresses fluids such as refrigerants or air and discharges the compressed fluids.
For example, a refrigerator has heretofore employed a system in which a compressor is used to compress a refrigerant and the compressed refrigerant is circulated through a circuit. As the systems of the compressor in this case, there are a rotary compressor called a rotary type compressor (e.g., see Japanese Patent Application Laid-Open No. 5-99172 (Patent Document 1)), a scroll compressor, and a screw compressor.
The rotary compressor has advantages that a structure is relatively simple and production costs are low, but there is a problem of increases in vibration and torque fluctuation. In the case of the scroll compressor and the screw compressor, there is a problem of high costs caused by bad workability while torque fluctuation is small.
Thus, there has been developed a system which disposes a swash plate as a rotary compression member in a cylinder and partitions compression spaces constituted below and above the swash plate by a vane to compress fluids (e.g., PCT No. 2003-532008 (Patent Document 2)). According to the compressor of such system, there is an advantage of constituting a compressor which is relatively simple in structure and small in vibration.
However, in the case of the structure of the Patent Document 2, since a high pressure chamber and a low pressure chamber are adjacent to each other below and above the compression member (swash plate) in the entire region of the cylinder, a difference between high and low pressures is enlarged, and refrigerant leakage causes a problem of efficiency deterioration
Especially in a case where one surface of the compression member is disposed on a driving element side, the refrigerant in the compression space easily leaks between a rotary shaft and a bearing of the rotary shaft, and a performance of the compressor has been degraded.
Moreover, even in the compressor having the structure described in Patent Document 2 described above, an oil reservoir is formed in a lower part of a sealed container in the same manner as in the conventional compressor of Patent Document 1 described above. Since oil is supplied from the oil reservoir to the compression element by an oil pump, there has occurred a problem that it becomes difficult to supply the oil by the oil pump, and the supplied oil is insufficient in a case where the compression element is disposed in a position distant from the oil reservoir, such as a position above the driving element.